at great Depths in the Sea. 



55 



the genus referred to. 



The chambers, as will be seen, are seven 

 in number, the smallest and oldest measuring ystg^ 1 °^ an mcn > 

 whilst the largest and last- developed 

 measures ^jgth of an inch. The en- 

 tire specimen presents the transparency 

 and delicacy of the normal Cocco- 

 spheres. No septal apertures are visi- 

 ble; but this may arise in a great 

 measure from the position of the spe- 

 cimen, which is preserved on a slide in 

 balsam, and also from the imperfect 

 manner in which it was necessary to 

 clean the deposit before mounting it. 

 On the exposed surface of each chamber the Coccoliths are di- 

 stinctly visible. That their adherence in this fashion is not 

 the result of accident is, I think, evident both from their dis- 

 position and the circumstance of numerous Foraminifera, pre- 

 sent throughout the whole of the same slide, and of equal 

 delicacy and transparency, not exhibiting a single Coccolith on 

 their surfaces, although great numbers occur around them on 

 every side. 



During my earlier examinations of these remarkable objects, 

 I repeatedly detected Coccoliths adherent to Globigerina-shells ; 

 but in no other instance than that just cited have I found the 

 whole, or indeed more than one chamber of any Foraminiferous 

 shell, so studded, and in other respects presenting appearances 

 so identical with those seen in the free Coccospheres of which 

 I have spoken. 



It is certainly strange that, during the examination of a large 

 series of slides exhibiting the lighter particles of the material in 

 which the Coccospheres and Coccoliths abound, only one good 

 example of a Foraminiferous shell should have been observed 

 in the condition alluded to, — the four Coccospheres spoken 

 of as occurring united in a linear series, although closely re- 

 sembling the Nodosarian type in point of arrangement, pre- 

 senting no positive evidence of their Foraminiferous origin. 

 But it must be borne in mind, in investigating the lower organic 

 forms of the animal and vegetable kingdoms, that instances 

 are far from rare in which early phases of development are so 

 ephemeral as to render the chances of their taking place under 

 the eye of the observer extremely scanty. And again, for reasons 

 already assigned, it is far from improbable that, although actually 

 present in the material under analysis, the appearances are con- 

 stantly overlooked. 



These minute bodies, however, possess a high degree of in- 

 terest apart from that arising from their association with the 



